Turn the Instant Pot to the saute setting and heat the oil.
Add the onion and garlic and saute until soft, about 2-3 minutes.
Break up the beef into the pot and cook for 3-4 minutes or until no pink remains in the beef.
Add the macaroni, broth, tomato paste, Worcestershire sauce, and salt and pepper.
Stir to combine. Be sure to scrape any cooked ground beef off the bottom.
Cover and set the Instant Pot to cook at high-pressure for 5 minutes.
When the cycle is complete, quick-release the pressure, remove lid and stir well.
Stir in the cheese a little at a time and serve immediately with fresh parsley or parmesan cheese if desired.
Store the leftovers in the refrigerator.